High level resistance to colistin mediated by various mutations in the crrB gene among carbapenemase-producing Klebsiella pneumoniae [PublishAheadOfPrint]

Mutations in the crrAB genes encoding a two-component regulator involved in modifications of the lipopolysaccharide were searched for among a collection of colistin-resistant Klebsiella pneumoniae isolates. Four isolates respectively producing carbapenemases NDM-1, OXA-181, or KPC-2 showed mutated CrrB proteins compared to wild-type strains. Complementation assays with a wild-type CrrB protein restored the susceptibility to colistin in all cases, confirming the involvement of the identified substitutions in the resistance phenotype.

http://ift.tt/2eE4OJ7